Federal Signal Corporation VISION, Инструкция по установке и обслуживанию

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C. Separate the two circuit boards by gently
pulling them apart.
D. Disconnect the green wire at the stud on
the keypad circuit board.
E. After repair or replacement, reconnect the
green wire and reassemble the control head. Reas-
semble the control head in its bracket (if used), and
insert the modular connector in the receptacle.
6-3. INTERFACE/RELAY UNIT.
A. General .
Any competent electronic technician should
have little difficulty in tracing a malfunction, should
any occur. For emergency replacement of any of the
small components, care must be used when soldering.
Heat easily damages transistors, capacitors and
circuit boards. It is therefore advisable to use
longnose pliers or a similar heat sink on the lead
being soldered.
CAUTION
To avoid damage to the unit, disconnect all
red wires to the unit at the battery
before proceeding.
B. Removal for Servicing .
When removing the chassis for servicing,
loosen the two hexagon head screws on the underside
of the unit, near the front edge. Slide the entire
chassis out of the case as shown in figure 6-2.
C. Printed Circuit Board Removal.
The Vision Interface/Relay Unit consists of
one circuit board. See figure 6-3.
To remove the circuit board, proceed as
follows:
1. Disconnect the wires from the terminal
strip TB1.
2. Disconnect the large red wire at
LUG1.
3. Unplug the control head cable and
lightbar control cable connectors.
4. Unplug the connector at J1 on the
circuit board.
5. The circuit board is secured to the
chassis by four stand-offs. Depress the locking tab on
each stand-off and gently lift the circuit board off the
stand-offs.
D. Control Head Fuse.
A solder-in sub-miniature fuse (F5 on the
circuit board) provides short-circuit protection for the
control head and cable. F5 is located between R12
and R13 (near J1) on the circuit board. Failure of this
fuse, although unlikely, will cause the Vision to be
completely inoperative. If failure of F5 is suspected,
proceed as follows:
1. Remove the circuit board as described
in 6-3.C. above.
2. Check the fuse for continuity with an
ohmmeter.
3. If fuse failure has occurred, replace
with an EXACT replacement (refer to paragraph 6-
6.).
NOTE
Failure of the control head fuse is usually the
result of a shorted control head cable, or the
control head cable was damaged during instal-
lation. Ensure that the cause of F5’s failure is
located and repaired before reapplying power
to the unit.
6-4. LIGHTBAR.
A. General .
Any competent electronic technician should
have little difficulty in tracing a malfunction, should
any occur. For emergency replacement of any of the
small components, care must be used when soldering.
Heat easily damages transistors, capacitors and
circuit boards. It is therefore advisable to use
longnose pliers or a similar heat sink on the lead
being soldered.
Figure 6-2. Chassis Removal.
6-2